Decision Optimization

Decision Optimization

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  • 1.  How to use Java function in OPL Model?

    Posted Sat April 08, 2023 10:03 AM
    Edited by Mohamed Awad Sat April 08, 2023 10:06 AM

    Hi,

    I have a question that I am struggling to get the answer for. I would like to read data from external excel file using the following code.

    execute {
  var excelFile = "path/to/excel/file.xlsx";
  var dataSource = new IloOplExcelDataSource(excelFile);
  dataSource.addTable("ProcessingTimes", "A1:D100");
  thisOplModel.addDataSource(dataSource);
}

int processingTime[allActivities];
int energyConsumption[allActivities];

execute {
  for (var da in allActivities) {
    var productType = da.activity.product_type;
    var activityType = da.activity.activity_type;

    // Get processing time and energy consumption from data source
    var processingTimes = oplModel.datasources.ProcessingTimes;
    var processingTimeRow = processingTimes[productType][activityType][1];
    var energyConsumptionRow = processingTimes[productType][activityType][2];
    var numRows = processingTimeRow.getSize();

    // Sample processing time and energy consumption from table
    var row = opl.rand(numRows)+1;
    processingTime[da] = processingTimeRow[row];
    energyConsumption[da] = energyConsumptionRow[row];
  }
}

    However, I receive the following error:
    Line 104: Element "IloOplExcelDataSource" does not exist in OPL model.

    Is there a way to solve that issue. I am using IBM ILOG CPLEX Optimization Studio Version: 22.1.0.0.

    Best regards,



    ------------------------------
    Mohamed Awad
    ------------------------------



  • 2.  RE: How to use Java function in OPL Model?

    Posted Tue April 11, 2023 04:55 AM

    Hi,

    Let me try to address your 2 questions:

    1) How to call java from OPL ?

    IloOplCallJava

    /*
IloOplCallJava : This function calls a Java method from a scripting block
*/

execute
{
  
var convert180toRadian = IloOplCallJava("java.lang.Math","toRadians", "", 180);
writeln("180 degrees in radian : ",convert180toRadian);
			    
}	

/*
180 degrees in radian : 3.141592654
*/	

execute
{
var title="title";
var msg="hello";  

IloOplCallJava("javax.swing.JOptionPane", "showMessageDialog",
"(Ljava/awt/Component;Ljava/lang/Object;Ljava/lang/String;I)V", 
null, msg, title, 1);	 
}  

execute{ 
writeln("5 random numbers");
var rnd = IloOplCallJava("java.util.Random", "<init>", "()");
rnd.setSeed(1);	
for(var i=1;i<=5;i++)
{			    			  
 var t = rnd.nextDouble();
 writeln(t);
}
writeln("Gaussian");
for(var i=1;i<=5;i++)
{			    			  
 var t = rnd.nextGaussian();
 writeln(t);
}
}


    2) Read an excel file in OPL : Use SheetRead

    https://github.com/AlexFleischerParis/oplexcel/blob/main/read1cell.mod

    int value=...; 

execute
{
  writeln("value=",value);
}

subject to
{
  
}

int value2=value+1;

/*
which gives
value=4
*/


    https://github.com/AlexFleischerParis/oplexcel/blob/main/read1cell.dat

    SheetConnection s("read1cell.xlsx");

value from SheetRead(s,"B1");

value2 to SheetWrite(s,"B5");





    ------------------------------
    [Alex] [Fleischer]
    [Data and AI Technical Sales]
    [IBM]
    ------------------------------

    Original Message


  • 3.  RE: How to use Java function in OPL Model?

    Posted Sat April 22, 2023 02:38 PM

    Hi Alex,

    Thank you for you reply. It will help to achieve what I am looking for. I have a question on:

    var rnd = IloOplCallJava("java.util.Random", "<init>", "()");

     
    How can I use IloOplCallJava to generate random integer number between upper and lower limits. I tried the following but it didn't work: 

    min + rnd.nextInt(max - min + 1);

    Could you please suggest a way to do that.

    Best regards,
    Mohamed 

     



    ------------------------------
    Mohamed Awad
    ------------------------------

    Original Message


  • 4.  RE: How to use Java function in OPL Model?

    Posted Sun April 23, 2023 03:55 AM

    Hi,

    many How to With OPL.

    To generate random numbers, no need to use java call from OPL, you can use rand:

    int m=10;
int M=15;

int sampleSize=20;

int sample[i in 1..sampleSize]=rand(M+1-m)+m;

execute
{
  writeln(sample);
}


    which gives

    [11 11 11 10 12 15 13 15 13 10 15 11 15 10 11 14 12 14 10 15]


    ------------------------------
    [Alex] [Fleischer]
    [Data and AI Technical Sales]
    [IBM]
    ------------------------------

    Original Message


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